Avoid Becoming a Skinny-Fat Person
One of the most important tools for achieving optimal wellness and aging gracefully is building and maintaining muscle. Muscle burns calories exponentially more efficiently than fat, and of course, it keeps us strong, active, and balanced. It is also part of the package that promotes a more youthful appearance.
Beginning in our late 30s or early 40s, we all begin to lose muscle, through some undetermined combination of aging, nutritional deficiencies, and inactivity. According to Nutrition Action Health Letter, April 2011, this translates into approximately a quarter of a pound of muscle loss per year for the average person. If left unchecked, the progressive loss, called sarcopenia, can profoundly affect our health and our appearance. Lost muscle can be replaced with unhealthy fat that either leads to being overweight and potentially plagued by associated diseases; or, alternatively, results in a skinny fat person who is also at increased risk for the same diseases. Since muscle weighs more than fat, a skinny fat person may register a fairly stable weight on the scale, but it is only an illusion.
As mentioned, muscle burns calories more efficiently, helping us maintain a healthy weight. The act of building muscle also stimulates bone growth, and produces an insulin-like protein that aids blood-sugar regulation. Adequate muscle mass and power is what enables us to maneuver in space and stay balanced. Sarcopenia contributes to an elders increased risk for falls, and adversely affects stamina, as well as the execution of everyday tasks, such as getting in and out of a chair.
To preserve your muscle mass and power you need to engage in regular strength training (a.k.a. resistance or weight training) at least twice a week. The American Heart Association and the American College of Sports Medicine counsel all healthy adults to establish a regimen that includes 8 to 10 strength training exercises that work the muscles of the chest, shoulders, arms, back, abdomen, and legs. You can accomplish this goal at a local gym or community center, or even at home. Traditional weight lifting is the more familiar modality, but today the functional fitness movement has introduced considerable variety into the formula. Functional fitness is based on the premise that we are meant to move in three dimensions. Workouts utilizing this principal can work more than one muscle at a time, and decrease the risk of injury while increasing the fun factor. Examples include kettlebells, resistance bands/tubes, medicine balls, stability balls, ropes, circuit training, and calisthenics, such as squats, lunges, chin ups, and planks. Many other activities can contribute to muscle conditioning, such as certain yoga moves, and squatting and lifting while tending the garden. Anyone, of any age, will benefit from attention to muscle health. To assist in this venture The National Institute on Aging provides the publication Exercise & Physical Activity Guide.
Protein consumption also builds muscle; however, research points to the fact that we may need more protein in our diet as we age. Currently, the Institute of Medicine recommends that adults consume 0.36 grams of protein per pound of body weight daily. Many people do not achieve this Recommended Daily Allowance (RDA), and now many researchers have raised the bar higher. They state that to maintain or gain muscle you may need to consume 25 to 50 percent more protein than the current RDA. That is closer to 0.5 grams of protein per pound of lean body weight for the average person, e.g. an individual who weighs 140 pounds would consume 70 grams of protein per day. Very active individuals and athletes may need to increase that formula to 0.8-1.0 grams per pound of lean body weight. The USDA provides the following nutrient database to reference protein content of foods.
The composition and source of the protein also plays a role in the effectiveness of muscle production. Of the 20 amino acid building blocks comprising protein, only 11 can be made by the body. The other 9 are called essential amino acids, because we need to obtain them from our diet. They are also the only amino acids that stimulate protein synthesis. Of the 9, leucine stands out as the driver behind the majority of protein synthesis. Animal proteins are rich in essential amino acids and leucine, and whey protein (20 percent of the protein found in milk) may rank highest in leucine concentration.
Plant proteins can suffice, especially soy, peanuts, almonds, chickpeas, lentils, sesame seeds, and other nuts, seeds, and legumes. An optimal level for leucine is not yet established, but currently the estimate is around 3 grams per meal. The amount of leucine in the diet also seems to be more important for older adults.
In addition, aging adults may need to spread their protein more evenly throughout the day. Indications are that the upper limit of protein for any one meal is about 30 grams. Consuming more than that at one sitting will not stimulate more protein synthesis, and, instead the calories will be utilized for energy or stored as fat. Dividing your calculated protein needs more evenly throughout the day will be more effective. For many Americans that means shifting some of the heavy protein associated with a typical dinner over to breakfast. Another vital point–protein is best utilized for muscle building within the first hour or two following strength training. So, plan accordingly for a timely snack or meal brimming with adequate protein.
A useful website for tracking your daily nutrient intake, as well as calorie intake and expenditures is www.fitday.com.
Ann Carey Tobin MD, FAAFP is a board-certified family physician. Her integrative medicine consultation practice, Partners in Healing, is located in Delmar.